PDC Test - Give 'Em a Hand

You can earn 0.25 PDC by passing the exam following this article, which has been approved for publication by NCRA's Council of the Academy of Professional Reporters.

The questions are based on the material in the article but some may require additional research. Send your answer sheet to NCRA's Continuing Education Office, 8224 Old Courthouse Road, Vienna, VA 22182, and enclose a check for $40 (member) or $50 (non-member) to cover the processing fee. 

Give 'Em a Hand

by Renée Cohen

Our hands are truly one of the most precious parts of our bodies. They not only enable us to use the tools that shape our human world, they are a tool in and of themselves. With our hands, we are able to acquire and eat food. We can also use our hands to have a crushing grip that saves or takes a life. Hands can sensitively communicate affection through touch as well as perform the minute movements that gently stitch fine threads of lace or sutures. Surgeons' hands are regularly entrusted to heal even the most delicate and vital of organs in the human body: the heart and the brain.

The following article covering the structural and functional anatomy of the bones and muscles of the amazing and unique human hand may act as a source of medical terms to add to your repertoire, or simply serve to give you a more complete understanding of what is going on when the hands of court reporters almost unconsciously comply with writing all voices in a room for hours at a time.

Despite the fact that the skin, muscles, cartilage and even the fingernail beds of the hand form before the bones, the bones are the underlying structure of the developed hand. There are 27 bones in the hand, many of which have the same names. These bones are essential and provide for our manual dexterity.

The bones of the hand, like bones elsewhere in the body, serve as muscle attachment points and a source of rigidity. If the hands were not bony, you can imagine that it would be impossible to have the dexterity that we have. How would you pick up your pencil if each time you contracted a muscle, another muscle stretched out a bit to compensate, meaning that your fingers would not move? We need bones attached to our muscles so that when a muscle contracts, it pulls the rigid bone along with it to create a substantial and specific movement with relative ease.

In order to make the hand and finger movements we want to, our hands must first be positioned where we would like them to be. As such, the main purpose of the arm is to position the hands generally to shield and protect the rest of the body and to use tools. The wrist connects this wide-scale arm movement with the finer movements of the fingers and the hand itself. Carpals are the eight cobblestone-shaped bones that compose the wrist. They are bound together by a network of sturdy but flexible ligaments. In medical terms, the wrist's carpal bones are named the navicular, capitate, styloid process, multangulars, hamate, lunate, triangular and pisiform.

In the hand itself we find the metacarpals. There are five metacarpal bones in the hand, which you can probably feel on yourself to understand their rough shapes and locations. Each carpal bone stretches from the base of the wrist to the first knuckle below the fingers, and the five are aligned next to each other as extensions of the fingers inside the hand. The main functions of the metacarpals are to assist in making precise finger movements and to provide attachment sites for the first dorsal interosseous muscles, which are the muscles you can feel along your pointer finger in the dip between that finger and the thumb. The metacarpals also provide an attachment site for the abductor pollicis brevis, which is the large, round muscle on the palm side of the thumb.

The fingers themselves consist of 14 bones, all of which are called phalanges. Each finger has three phalanges, except the thumb, which has only two. Interestingly enough, the phalanges' ability to move comes primarily from the long muscles of the forearm which connect with tendons on the palm side of the hand. When you decide to move your fingers, a forearm muscle contracts, pulling on a tendon. This tendon pulls on the phalange bone and the finger moves, corresponding to the muscle's tension. This is why you can see and feel muscles in your forearm moving about when you make a fist or move any of your phalanges.

Perhaps the most amazing part of the human hand is the thumb. Humans have what is known as an opposable thumb, which might not seem very impressive until you consider that it makes a phenomenal contribution to human life. Having opposable thumbs means that we can position our thumbs such that they face the other fingers very easily. Dogs and cats, for example, have similar bones in their forearms and paws but they do not have any opposable phalanges. This could very likely be why they do not rely on their paws to deliver food to their mouths and why they very rarely make use of tools of any sort.

Opposable thumbs are what allow us to make pinching motions with our fingers or to grab or hold onto objects with our whole hand. This configuration enables us to write, pick up small objects and work carefully with them, and, in general, assists in making most of the fine movements we are able to perform with our hands. An enormous amount of human activities are directly attributable to the fact that we can make this one simple movement with our thumbs that opposes them to the other fingers.

In more ways than one, our hands make us who we are. As a species, our opposable thumbs are responsible for an extremely wide variety of fine movements that distinguish us as vastly different creatures from the other animals on our planet. As individuals, it is our fingerprints that make us totally unique human beings.

About the Author:
Renée Cohen is a JCR Contributing Editor.

CEU Exam

1. What part of the human hand forms last?

a) skin
b) bone
c) muscles
d) fingernail beds

2. There are bones in the human hand.

a) 72
b) 43
c) 27
d) 8

3. The fact that our finger bones are rigid is of little relevance to our dexterity.

a) True
b) False

4. The bones of the hand serve as muscle attachment sites.

a) True
b) False

5. The main purposes of the arm include positioning the hand:

a) to use tools
b) to shield the body
c) to eat
d) a and b only

6. The wrist serves to connect broad movement with fine movement.

a) True
b) False

7. The cobblestone-shaped bones of the wrist are known as the:

a) metacarpals
b) carpals
c) ligaments
d) metatarsals

8. There are _____ metacarpals.

a) 8
b) 5
c) 14
d) 27

9. Metacarpals assist in:

a) providing attachment sites for dorsal interosseous muscles
b) making precise finger movements
c) providing attachment sites for abductor pollicis brevis
d) all of the above

10. The abductor pollicis brevis is:

a) too small to detect from outside the hand
b) a relatively large muscle at the base of the thumb
c) the muscle that bends the hand up and down
d) none of the above

11. How many phalanges are found directly under the fingernails and in between the knuckles of the fingers?

a) 14
b) 16
c) 18
d) 20

12. Phalanges move mostly with the aid of:

a) the carpals
b) the abdutor pollicis brevis
c) forearm muscles
d) upper arm muscles

13. It is normal to see movement in the wrist or lower forearm when a person makes a fist because the muscles and tendons that control this action pass through the wrist.

a) True
b) False

14. Opposable digits are fingers that can face each other or make pinching motions easily.

a) True
b) False

15. Opposable thumbs allow humans to:

a) write
b) pick up small objects
c) hold and manipulate tools
d) all of the above

16. Fingerprints are the same:

a) often
b) rarely
c) never
d) occasionally

17. Carpal tunnel syndrome is:

a) a brachial plexus disorder
b) a bacterial problem
c) a vein entrapment disorder
d) a peripheral nerve entrapment disorder

18. Carpals are found at:

a) the connection of the phalanges and metacarpals
b) the connection of the radius and ulna
c) the center of the hand
d) none of the above

19. Keratin is found in fingernails.

a) True
b) False

20. The Amish have a gene that occasionally leads to 12-fingered children.

a) True
b) False